In last month's sci-fi blockbuster Event Horizon we saw Sam Neil go to Hell on a spaceship and meet assorted "demons" appearing as familiar people from his past. This month, we see Jodie Foster in Contact go to Heaven on a spaceship and, blow me, meet "angels" in the forms of people from her past.

Now the news comes along that a similar film, Sphere, is finally in post-production in the US. Sphere, starring Dustin Hoffman, features the crew of a hi-tech submersible descending into the deepest part of the oceans and encountering pretty much the same deal: alien beings appearing as celestial ones, and taking on the heart-stopping appearance of the dead.

Science fiction in the movies is growing increasingly bipolar, alternately exhilarated by the vistas of new technology and depressed by pre-millennial tension. On the one hand, we have the Independence Day scenario, ugly monsters with ray-guns and absurdly concocted languages (full marks to Tim Burton for satirising that particular lame convention in Mars Attacks! - the aliens just bark like crazed chihuahuas). On the other, we have quasi-religious, over-portentous fears of the coming apocalypse.

Babylonian horrors couched in SF terms have been stalking popular culture for the last decade, from Alan Moore's innovative comic books to the ever-expanding X-Files stable and the several series of Babylon 5. The ancient city of Babylon was, after all, where Judaism absorbed its Zoroastrian ideas, creating the apocalyptic book of Daniel in the process. So why is Babylon 5 suddenly more popular than the perennially popular Star Trek? Simply because it gravitates towards the opposite pole to Star Trek's optimistic techno-hubris, or seemed to for a while, at least, before the creepy spider-beings that wished to cloak the universe in darkness were revealed as just another race with advanced technology.

Modern SF is as much about religion as it is about science. The religious markers in Contact are there for everyone to see, from Noah to the New Testament. Matthew McConaughey's character, Palmer Joss, who becomes religious adviser to the fictional President in Contact, acts as a kind of Joseph figure for the Virgin Jodie: chaste, supportive and with a hard- to-read peripheral role in the unfolding drama. When Jodie Foster's character first hears the sound of an alien transmission on her portable computer in some South American grasslands, we observe her on her own, in a solitary and almost pastoral context. The image of her with her hand cupped to her ear, listening intently to the whispering sounds from outer space, immediately brings to mind the Annunciation iconography of the Renaissance, where the Virgin Mary is told she is to bear a child. And just to confirm the Florentine iconography, a line of radiotelescopes vanishes behind her like tilted church cupolas, receding in perfectly ordered 16th-century perspective.

When Foster receives instructions on how to build a ship, instructions that come encoded within the images of a 1930s TV broadcast by Adolf Hitler, she could as well be Noah, receiving his plans from God on how to build the Ark. That this ark is, to all intents and purposes, an ovum, brings the motif of the Virgin birth full circle.

Yet the way the spaceship works is entirely heretical. Perhaps they should have dubbed the mechanism, a huge swivelling gyroscope into which a manned capsule is dropped, "gnostic-drive" after the Christian and Sufi tradition that more-or-less eschewed formal religion in favour of inner searchings. For after the journey, Jodie's spaceship doesn't actually appear to have gone anywhere.

A remarkably similar gyroscopic engine, one that opens a "dimensional gate in folded space", is present in the Event Horizon, the eponymously named cruciform-shaped spaceship that the film's designers have said that they consciously evolved from the architecture and facade of Notre Dame in Paris. Even the medical facilities look designed by the Spanish Inquisition. Horrible visions and images from the past flood the minds of those unfortunate enough to be sent to rescue the Event Horizon when it unexpectedly reappears from its journey to nowhere. This is a cloistered zone of medieval guilt and retribution.

It turns out that the Event Horizon's engine has actually opened a portal to Hell itself, creating a kind of plughole to damnation that the 18th- century mystic Emmanuel Swedenborg would have recognised immediately, when he described the other-worldly vistas of his visions, and the terrifying demons that inhabit them (come to think of it, some sounding exactly like Ridley Scott's Alien: bony-faced fiends whose faces are "nothing but teeth"). The idea of Hell as the fifth dimension has long been hovering in "horror" culture, from the 1940s writer HP Lovecraft through to films such as Hellraiser and Jacob's Ladder. Hell, it seems, is much nearer than Heaven. These films are giving a very ancient moral message. Heaven has to be yearned for and travelled to. Hell merely seeps into our lives unbidden.

If the millennial frissons currently being handed down by Hollywood and the US networks are beginning to pall, spare a thought for their progenitor, Andrei Tarkovsky. His film Solaris (1972) explored exactly the same metaphors in a somewhat more sophisticated way, perhaps emboldened by Kubrick's hugely influential 2001. In Tarkovsky's film, a spaceship trapped in orbit round a quixotic, unidentified planet generates disturbing hallucinations and visions for those on board.

Tarkovsky, who died in Sweden in 1986, would no doubt have been horrified at the use his metaphysical film Solaris was being put to by the barons of Hollywood. Austere in intellect, reflective of spirit and much given to quotation of his father (a famous poet), Tarkovsky firmly believed in films as a method of instruction rather than a form of entertainment. He also, according to film historian Graham Petrie, consistently attacked modern man's insistence on using technology as "a solution to human problems", and the idea of using technology to get to Heaven or Hell would have appalled him.

In a recent book, Open Sky, the brilliant French thinker Paul Virilio directly addresses many of the themes crudely now touched on by mainstream SF movies and TV: how technology has shrunk space, and is now shrinking time also, causing serious perceptive disorders. Virilio predicts a "generalised accident", a collective breakdown in our relationship with time, something more catastrophic than any biblical tumult or fiery apocalypse. "Eliminating distance kills," he headlines one chapter, quoting Rene Char. And it's no coincidence that, in all these films - Contact, Event Horizon and Sphere - there's an increasing concern with the idea of the collapse of reality as a preamble to Armageddon.

And there's also something else you should know. If you go to see Contact in London, beware. According to James Manning's new book, Prophecies for the New Millennium, you may well find yourself eating popcorn next to the actual Antichrist or the next Messiah. The new Buddhist Maitreya is apparently living quietly in the Pakistani community in London, and the Antichrist has been seen on the fringes of "Cool Britannia" by no less a personage than Paco Rabanne.